Convenient and small near-ground atmospheric-boundary-layer wind tunnel and its application in human exposure risk assessment

Abstract

The present invention discloses a convenient and small near-ground atmospheric-boundary-layer wind tunnel and its application in the human exposure risk assessment. This near-ground atmospheric-boundary-layer wind tunnel comprises a wind tunnel body and a reflux stabilizer; the wind tunnel body comprises a natural wind injection device and a simulation test device, with the natural wind injection device, the simulation test device and the reflux stabilizer connected in sequence; the natural wind injection device comprises a pipe fan, a swirl mixing pipe, a diffusion homogenizer, and a cyclone distribution pipe connected in sequence; the diffusion homogenizer is provided inside at the center with an inner member for preventing flow separation; and a static mixing spiral rod is welded on the inner wall surface of the swirl mixing pipe. The measurement of the atmospheric-pollutant environmental migration and transformation behavior through this wind tunnel reduces the floor area of the wind tunnel and saves the investment. The wind tunnel can allow research of the environmental migration and transformation process of near-ground atmospheric pollutants in a local area and assessment of the impact of the near-ground atmospheric pollutants on the population health.

The invention claimed is: 
     
       1. A convenient and small near-ground atmospheric-boundary-layer wind tunnel, characterized in that: the near-ground atmospheric-boundary-layer wind tunnel comprises a wind tunnel body and a reflux stabilizer; the wind tunnel body comprises a natural wind injection device and a simulation test device, with the natural wind injection device, the simulation test device and the reflux stabilizer connected in sequence; the natural wind injection device comprises a pipe fan, a swirl mixing pipe, a diffusion homogenizer, and a cyclone distribution pipe connected in sequence; the diffusion homogenizer is provided inside at the center with an inner member for preventing flow separation; and a static mixing spiral rod is welded on the inner wall surface of the swirl mixing pipe. 
     
     
       2. The convenient and small near-ground atmospheric-boundary-layer wind tunnel according to  claim 1 , characterized in that: the natural wind injection device is provided with a tangential air inlet and an axial vent, and the swirl mixing pipe is provided with an outer pipe and an inner pipe, with the outer pipe connected to the pipe fan through the tangential air inlet; and the axial vent is provided with a static blade, a vortex baffle, and a porous medium filling member. 
     
     
       3. The convenient and small near-ground atmospheric-boundary-layer wind tunnel according to  claim 1 , characterized in that: the inner member for preventing flow separation is made of temperature-resistant and corrosion-resistant material (silicon carbide, graphene or stainless steel), and has the shape of a ring, a spiral or a fan blade; and the static mixing spiral rod comprises a bundle of porous corrugated plates or a group of spiral rods. 
     
     
       4. The convenient and small near-ground atmospheric-boundary-layer wind tunnel according to  claim 1 , characterized in that: the reflux stabilizer comprises an elbow pipe, an air induction pipe, a reducer and a reflux pipe that are connected; the elbow pipe comprises a first elbow pipe, a second elbow pipe and a third elbow pipe; the first elbow pipe is connected at both ends to the simulation test device and the air induction pipe, respectively; the air induction pipe is connected to the second elbow pipe, which is connected to the reflux pipe; the reducer is connected at both ends to the reflux pipe and the third elbow pipe, respectively; and the third elbow pipe is connected to the pipe fan. 
     
     
       5. The convenient and small near-ground atmospheric-boundary-layer wind tunnel according to  claim 4 , characterized in that: the elbow pipe and the reflux pipe have the shape of a square or a ring, and a cross-sectional area of 0.01-1 m 2 ; and the reducer and the reflux pipe have a pipe length of 0.1-10 m. 
     
     
       6. The convenient and small near-ground atmospheric-boundary-layer wind tunnel according to  claim 1 , characterized in that: the simulation test device is communicated at both sides and/or the upper portion with the atmosphere through an exhaust box, whose wall surface is trumpet-shaped and has a porous structure. 
     
     
       7. The convenient and small near-ground atmospheric-boundary-layer wind tunnel according to  claim 6 , characterized in that: the simulation test device is provided inside with a terrain model, which is provided with a sampling hole, a sample inlet, or a groove with a culture medium; the sampling hole and the sample inlet have the shape of a circle, an ellipse, a rectangle or a polygon, and a cross-sectional area of 0.001-1 m 2 . 
     
     
       8. The convenient and small near-ground atmospheric-boundary-layer wind tunnel according to  claim 7 , characterized in that: the terrain model is provided on the surface with more than one of waterways, biomarkers, and materials with a temperature control function. 
     
     
       9. The convenient and small near-ground atmospheric-boundary-layer wind tunnel according to  claim 8 , characterized in that: the biomarkers are  Taxiphyllum taxirameum, Sphagnum, Pleurozium schreberi, Barbula subcontorta  Broth,  Funaria hygrometrica, Hypnum plumaeforme  or hoppers; the materials with the temperature control function are one or more of polyurethane, polyethylene, polystyrene, foam glass, magnesium oxide, nanosilica, and aluminum, with a thermal conductivity λ of 0.001-250 W/(m·K). 
     
     
       10. Application of the convenient and small near-ground atmospheric-boundary-layer wind tunnel according to any of  claim 1  in assessment of near-ground atmospheric-pollutant diffusion and human exposure risks in a local area, or assessment of impact of a transport and transformation process of environmental pollutants on human health.